Biometric identification systems that do not require a target's cooperation are enjoying great popularity and demand among governmental authorities and companies where security is of importance, such as airports, banks, workplaces and other secure or restricted places. For instance, systems employing biometric facial recognition, unlike security systems that require target cooperation (e.g., fingerprint recognition, iris recognition, etc.), require no human cooperation, awareness, or contact. These systems can work passively at a distance in a real time environment.
Conventional systems and methods for biometric facial recognition typically use 2D images of a person's face, similar to images received from video or photo cameras. Although 2D image data is easy to collect, it is not uniquely distinctive and the quality of the acquired data is dependent on a variety of conditions, such as ambient light conditions, view angle, etc. Consequently, the reliability of 2D biometric facial recognition systems lags behind many conventional security systems that use biometric data, such as fingerprints, retinal eye patterns, or hand geometry, to identify a person. Some conventional systems, such as those only capable of capturing 2D image data, experience difficulty in isolating a target image, such as a person's face, from other targets. These systems also experience accuracy problems because the quality of the acquired data is negatively affected by shadows or movement by the person to be identified.
3D images, in contrast, are not negatively affected by any movement or position of the target to be identified and do not depend on the texture and color of the skin. Since 3D images carry more information about the target than 2D images, it is desirable to use 3D images in biometric identification systems. In addition, it is desirable to have a system that simultaneously captures an image of a 3D surface of a target for automated recognition, for example, and a 2D photographic image of the target that can be used for passport, driver licenses, and other identification documents which can be used as a back-up or confirmatory identification system.